Finish suitable for a cup?

[azamiryou]

I have in mind to turn a beverage cup from wood, and I'm looking for ideas of what to use as a finish. The finish should:

1 - seal the wood so that the beverage does not escape or seep through.
2 - be washable
3 - not break down in alcohol or a mild acid (such as citrus juice or milk)

It would probably also be good if it didn't release toxins or carcinogens into the beverage.

Any suggestions?

 

[Justturnin]

I think Tung Oil is the original wood safe finish. Many coats and allow it to cure and harden in the wood. You can apply until it is a gloss coat and water will bead off. If you need to refinish you just reapply some more oil. This is the 100% Tung oil not the "Blends" that you get at the box stores.

 

[Holz Mechaniker]

I know of a guy that used Kraft Kote which is what is used as a finish for Bar Tops.
OF any finish remember that it must CURE to be considered food safe.

 

[alamocdc]

Most finish makers (and many wood workers) will tell you that just about any finish available is food safe once properly cured. That said, you must also be aware that food safe doesn't mean every consumable imaginable. Many lilke walnut oil, but it can and does go rancid. Tung and Boiled Lindseed oils take quite awhile to cure and I don't know how well they hold up in acidic conditions (think fruit juices). Alcohol will slowly dissolve lacquer. Polyurethane finishes (even water based) are not truly water proof. As far as I am concerned, only one finish is harmless. And it protects the wood pieces just fine. I use nothing but mineral oil on anything I make that comes in contact with food and drink. It is cheap and never goes rancid (only oil that won't). JMNSHO

 

[KenV]

Epoxy and plan on occasional refresh to meet your specs. Hand wash only or much more frequent refresh.

Personally I use Mahoney or Doctors Walnut Oil, which does not go rancid, and refresh it more often. Polymerization is fairly fast.

 

[BRobbins629]

I know some who use CA

 

[TellicoTurning]

I've pretty much stuck to the polyurethane finishes... I use the Minwax wipe on poly on almost all of my wood turnings.... after it sits about 2 weeks, it will be fully cured and food safe... one quick check is... if you can smell it, it still needs to cure.

 

[The Penguin]

I sat in a demo by Barbara Dill over the weekend at SWAT - she uses CA on the inside of her cups.

 

[TellicoTurning]

I've never used CA, but have used a plexiglas solution to "paint" the inside of some of my wood mugs... you'll need to sand between coats to get a smooth finish inside.